Polyolefins are of great interest in industry as they have many uses in many different areas. For example, polyolefins, such as polyethylene and polypropylene, are often used in everything from waxes and plasticizers to films and structural components. Of late many have been interested in modifying the architecture of such polyolefins in the hopes of obtaining new and better combinations of properties. One method of controlling polyolefin architecture is to select monomers that will impart specific characteristics or tailoring the monomers used. For example, several have tried to produce large “monomers” called “macromonomers” or “macromers” having amounts of vinyl, vinylidene or vinylene termination that can be polymerized with smaller olefins such as ethylene or propylene to impart long chain branching, structural properties, etc. to a polyolefin. Typically, vinyl macromonomers are found more useful or easier to use than vinylene or vinylidene macromonomers.
Vinyl-terminated (VT) polyethylene (PE) and poly(ethylene/propylene) have been used as macromonomers with propylene copolymerization for the synthesis of long chain branched polymers. These VT-macromonomers, generated in situ or isolated prior to use, can for example be used to afford comb-like polyolefins, with improved properties such as processability, even for low macromonomer incorporation. Yet, the oligomerization of at least some types of macromers with a high degree of polymerization has been elusive.